Crawl any site, no limits on number of pages and ability to get a very detailed report on links, errors and strucutre of the site, all for free:
https://home.snafu.de/tilman/xenulink.html
Ability to crawl and save a website into static html files. Point this at any site and it will convert even the most complex site into a simple working html version of the site.
Want to understand why your site might be slow, these 2 tools are the ones you need to use. Both are free and both give you detailed info on what is causing the problems and how to fix them.
https://developers.google.com/speed/pagespeed/insights/